Sheet-post-process apparatus

ABSTRACT

In a sheet post-process apparatus of the present invention, a gate for branching sheets of paper ejected from an image forming apparatus to a conveying path of sheets of paper requiring a post process and a conveying path of sheets of paper requiring no post process is installed and a paper ejection tray receives either of sheets of paper post-processed and sheets of paper not post-processed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 2004-285354, filed on 29 Sep. 2004 and No. 2004-366524, filed on 17 Dec. 2004, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a sheet post-process apparatus for post-processing sheets of paper ejected from an image forming apparatus such as a copier, a printer, or a composite device.

2. Description of the Related Art

In recent years, in an image forming apparatus, to post-process sheets of paper after image forming such as sorting or stapling sheets of paper, a sheet post-process apparatus may be installed in the neighborhood of the paper ejection unit of the image forming apparatus body. In such a sheet post-process apparatus, after waiting for ending of the sheet post-process of preceding sheets, the post-process of succeeding sheets is performed. To make the succeeding sheets ejected from the image forming apparatus body stand by like this, conventionally, a shifting path such as a standby tray may be installed halfway the path toward the stapling unit (for example, Japanese Patent Application 2004-155551).

However, when ejecting sheets of paper not to be post-processed and sheets of paper to be post-processed to the paper ejection tray via the same path, the image forming speed of the image forming apparatus must be adjusted.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the essential section of the sheet post-process apparatus relating to an embodiment of the present invention.

FIG. 2 is a top view showing the essential section of the sheet post-process apparatus relating to an embodiment of the present invention.

FIG. 3 is a schematic block diagram showing the sheet post-process apparatus relating to an embodiment of the present invention.

FIG. 4 is a perspective view showing the stapler of the sheet post-process apparatus relating to an embodiment of the present invention.

FIG. 5 is a perspective view showing the vertical matching roller relating to an embodiment of the present invention.

FIG. 6 is an illustration showing the paddle relating to an embodiment of the present invention.

FIG. 7 is a schematic perspective view showing the standby tray and processing tray relating to an embodiment of the present invention.

FIG. 8 is a top view showing the standby tray and processing tray relating to an embodiment of the present invention.

FIG. 9 is a schematic perspective view showing the horizontal matching plate and conveyor belt relating to an embodiment of the present invention.

FIG. 10 is an illustration showing the state of pressed-out sheets on the standby tray or paper ejection tray relating to an embodiment of the present invention.

FIG. 11 is an illustration showing movement of the standby tray relating to an embodiment of the present invention.

FIG. 12 is a schematic block diagram showing the gate G relating to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Throughout this description, the embodiments and examples shown should be considered as exemplars, rather than limitations on the apparatus and methods of the present invention.

Hereinafter, the embodiment of the present invention will be explained in detail with reference to the accompanying drawings.

Further, to the same parts shown in the drawings, the same numerals are assigned and duplicated explanation will be omitted. FIG. 1 is a perspective view showing the essential section of a sheet post-process apparatus 7 relating to an embodiment of the present invention, and FIG. 2 is a top view of the essential section of the sheet post-process apparatus relating to an embodiment of the present invention, and FIG. 3 is a schematic block diagram showing the sheet post-process apparatus 7 arranged in the neighborhood of an image forming apparatus 5 such as a copier.

The sheet post-process apparatus 7 is basically composed of a standby tray 10, a processing tray 12, a stapler 14, a first paper ejection tray 16, and a second paper ejection tray 18.

A sheet of paper P on which an image is formed by the image forming apparatus 5 such as a copier and is ejected from a pair of paper ejection rollers 6 is received by a pair of entrance rollers 22. The entrance rollers 22 are composed of an upper entrance roller 22 a and a lower entrance roller 22 b. The entrance rollers 22 are driven by an entrance roller motor 26.

As shown in FIG. 12, on the downstream side of the entrance rollers 22, a gate G for branching the sheet of paper P received by the entrance rollers 22 to two paths (flow paths) is installed. The gate G has a cross section in a wedge shape and the sharp-pointed part of the wedge shape is directed to the neighborhood of the rolling surfaces of the entrance rollers 22. The gate G is rotatably born by the side wall in the post-process apparatus 7. The sharp-pointed part of the wedge shape is set at the first position almost pointing the entrance roller 22 a and the second position almost pointing the entrance roller 22 b.

Namely, the first position is a position for selecting the path for the sheets of paper P requiring the post process and the second position is a position for selecting the path for the sheets of paper P requiring no post process.

When the gate G is at the first position, the sheets of paper P are fed to the first paper feed rollers 24 and is sent to the standby tray 10 from the first paper feed rollers 24.

Between the entrance rollers 22 and the standby tray 10, a paper path ceiling 36 for leading the sheets of paper P to the first paper feed rollers 24 is installed. The first paper feed rollers 24 are composed of an upper paper feed roller and a lower paper feed roller.

Under the standby tray 10, the processing tray 12 for loading the sheets of paper P dropped and fed from the standby tray 10 is arranged.

The processing tray 12, while the sheets of paper P are stapled by the stapler 14 which is a processing mechanism for performing the post-process, matches and supports the sheets of paper P to be loaded.

As shown in FIG. 7, when a predetermined number of sheets of paper is accumulated on the standby tray 10, standby tray parts 10 a and 10 b are opened left and right on the drawing by a standby tray motor 34 and the sheets of paper P are dropped by their own weight on the processing tray 12.

As shown in FIG. 4, the stapler 14 is positioned by a stapler driving unit 49 and the stapling process is controlled. The processing tray 12 has a pair of upper vertical matching roller 38 a and lower vertical roller 38 b for matching a plurality of sheets of paper P dropped and fed from the standby tray 10 in the vertical direction which is a conveying direction (refer to FIG. 5). The upper and lower vertical matching rollers 38 a and 38 b serve as bundle conveying rollers for holding a paper bundle T after stapled and taking out it from the stapler 14. The upper vertical matching roller 38 a is driven by a vertical matching upper roller motor 40. The lower vertical matching roller 38 b is driven by a vertical matching lower roller motor 42.

When the sheets of paper P are dropped and fed on the processing tray 12, at the position where the rear end of each of the sheets of paper P is dropped, a rotatable paddle 44 for matching vertically the uppermost sheet of paper P loaded on the processing tray 12 is arranged. The paddle 44, as shown in FIG. 6, has a receiving portion 44 a of the sheets of paper P dropped and fed onto the processing tray 12, a beating portion 44 b for beating down the sheets of paper P on the processing tray 12, and a feeding portion 44 c for matching the sheets of paper P on the processing tray 12 and it is driven by a paddle motor 46. The paddle 44 is composed of an elastic rubber material.

At the end of the processing tray 12 on the side of the stapler 14, a stopper 45 for making contact with the rear end of each of the sheets of paper P and controlling the rear end position. Almost at the center of the processing tray 12, a conveyor belt 50 for conveying the paper bundle T, which is stapled and taken out from the stapler 14 by the upper and lower vertical matching rollers 38 a and 38 b, up to the first or second paper ejection tray 16 or 18 is installed. To the conveyer belt 50, a feed pawl 50 a for hooking the rear end of the paper bundle T is attached.

The standby tray 10 can drop and feed the sheets of paper P onto the processing tray 12 and also can convey the sheets of paper P toward the first or second paper ejection tray 16 or 18. When conveying the sheets of paper P toward the paper ejection trays 16 and 18, a standby tray roller 28 for matching the sheets of paper P makes contact with the sheets of paper P on the standby tray 10. The standby tray roller 28 is controlled in the vertical movement by a standby tray roller driving source 30 and is driven to rotate by a standby tray roller motor 32.

The standby tray 10 supports the sheets of paper P so as to position the front ends thereof higher than the rear ends thereof, so that it is arranged at a tilt angle of θ 1. The first or second paper ejection tray 16 or 18 is moved up and down by a paper ejection tray driving unit 52 and either of them is selected. The first or second paper ejection tray 16 or 18 is moved up and down up to almost the same height as that of the standby tray 10 or the processing tray 12 when loading the sheets of paper P to improve the consistency of the sheets of paper P to be ejected. The first or second paper ejection tray 16 or 18 supports the sheets of paper P so as to position the front ends thereof higher than the rear ends thereof, so that they are arranged at a tilt angle of θ 2.

As shown in FIGS. 7 and 8, the standby tray 10 has a pair of tray members 10 a and 10 b formed so as to project from the wall face thereof, receives the sheets in a state that it slides in the width of the paper P and supports both sides of the paper P. On the tray members 10 a and 10 b, standby stoppers 10 c and 10 d for controlling the rear ends of the sheets of paper P are installed.

The standby tray 10 slides and moves by the standby tray motor 34. Between the standby tray 10 and the processing tray 12 where it reaches, when dropping and feeding the sheets of paper P from the standby tray 10 onto the processing tray 12, horizontal matching plates 47 a and 47 b shown in FIG. 9 for preventing the sheets of paper P from turning away in the horizontal direction perpendicular to the conveying direction and matching them horizontally are installed. The horizontal matching plates 47 a and 47 b are formed slidably so as to fit to the width of the sheets of paper P by a horizontal matching motor 48.

When the gate G is at the second position, the sheets of paper P requiring no post process are fed to second paper feed rollers 60 and furthermore are fed to third paper feed rollers 61. The second paper feed rollers 60 and the third paper feed rollers 61 are respectively composed of upper paper feed rollers 60 a and 61 a and lower paper feed rollers 60 b and 61 b.

A paper path 63 for leading the sheets of paper P from the entrance rollers, which are branched at the gate G, to the second paper feed rollers 60 is installed. Further, between the second paper feed rollers 60 and the third paper feed rollers 61, a separate paper path may be installed. The reason is that the sheets of paper P can be conveyed surely.

Under the third paper feed rollers 61, as mentioned above, the first paper ejection tray 16 is arranged. The first paper ejection tray 16 receives either of the sheets of paper P which are post-processed and the sheets of paper P which are not post-processed.

Next, the operation of the invention will be described. When an image is formed by the image forming apparatus 5 and a sheet of paper P is fed from the paper ejection rollers 6, the sheet post-process apparatus 7, depending on a case of performing the post-process of the sheet of paper P or a case of performing no post-process, or while the preceding sheet of paper P is in execution of the post-process or the post-process is finished, performs a different operation.

When the post-process is not performed, the sharp-pointed part of the wedge shape of the gate G is at the second position almost pointing the lower entrance roller 22 b. The sheets of paper P fed from the entrance rollers 22 are fed to the second paper feed rollers and are furthermore fed to the third paper feed rollers. The sheets of paper P fed from the third paper feed rollers are ejected to the first paper ejection tray 16.

In this way, on the first paper ejection tray 16, sheets of paper are sequentially loaded. The first paper ejection tray 16 is arranged at a tilt angle of θ 2 and the front end of the sheet of paper is positioned higher than the rear end thereof, so that for example, even if the sheet of paper P is fed to the first paper ejection tray 16 in a state that it is curled convexly as shown by a dotted line in FIG. 10, the preceding sheet of paper P loaded on the first paper ejection tray 16 is not pressed out by making contact with the front end of the succeeding sheet of paper P. Namely, the ejected sheet of paper P is sequentially loaded on the first paper ejection tray 16 unless the order is disturbed. Even if the preceding sheet of paper P is pressed by the succeeding sheet of paper P and is slightly displaced, since the tilt angle is θ 2, the sheet of paper P drops by its own weight and is loaded on the first paper ejection tray 16 with the rear end matched, and the ejection process of the sheet of paper is completed.

Next, a case that the stapling process which is a post-process is to be performed and no preceding sheet of paper P in execution of the stapling process exists on the processing tray 12 will be described. At this time, the standby tray 10 slides and moves the tray members 10 a and 10 b respectively up to the positions indicated by the dotted lines in FIG. 11 in the directions of arrows m and n and opens the dropping and feeding path of the sheet of paper P. The horizontal matching plates 47 a and 47 b, to match the sheet of paper P dropping from the paper feed rollers 24 in the horizontal direction, are arranged so that the gap between the horizontal matching plates 47 a and 47 b is made almost equal to the width of the sheet of paper P. By doing this, the sheet of paper P fed by the paper feed rollers 24, without the conveying being obstructed by the standby tray 10, is dropped and fed directly onto the processing tray 12.

At the time of dropping and feeding, the upper vertical matching roller 38 a is shifted upward and the receiving portion 44 a of the paddle 44 receives the rear end of the sheet of paper P. Both sides of the sheet of paper P drop in contact with the horizontal matching plates 47 a and 47 b and are matched in the horizontal direction. Then, the paddle 44 rotates in the direction of an arrow o, drops the rear end of the sheet of paper P from the receiving portion 44 a, and beats down it onto the processing tray 12 by the beating portion 44 b. Furthermore, the paddle 44 feeds the sheet of paper P in the direction of an arrow q by the feeding portion 44 c, and the rear end of the sheet of paper P makes contact with the stopper 45, and the vertical matching of the sheet of paper P is completed. Further, the vertical matching of the sheet of paper P on the processing tray 12 may be executed by the upper vertical matching roller 38 a by moving up and down each time.

In this way, the sheet of paper P on which an image is formed is loaded directly on the processing tray 12 from the paper feed rollers 24 while sequentially matching it in the horizontal direction and vertically direction. When the sheets of paper P reach a predetermined number, the stapler 14 staples the sheets of paper P on the processing tray 12 at a desired position and bundles them to form the paper bundle T. [page 8] Hereafter, the upper vertical matching roller 38 a is moved down onto the paper bundle and the paper bundle T is held between the upper vertical matching roller 38 a rotating in the direction of the arrow r and the lower vertical matching roller 38 b rotating in the direction of the arrow s and is conveyed toward the first paper ejection tray 16. When the rear end of the paper bundle T passes the upper and lower vertical matching rollers 38 a and 38 b, it is hooked by the feed pawl 50 a of the conveyor belt 50 rotating in the direction of the arrow t and is sent onto the first paper ejection tray 16.

At this time, the first paper ejection tray 16 slides and moves from the position indicated by the dashed line in FIG. 3 to the position indicated by the solid line. The first paper ejection tray 16 is arranged at a tilt angle of θ 2 and the front end of the sheet of paper is positioned higher than the rear end thereof, so that the preceding sheet of paper P sent onto the first paper ejection tray 16 is not pressed out by making contact with the front end of the succeeding paper bundle T. Further, even if the preceding paper bundle T is slightly displaced by the succeeding sheet of paper P, since the tilt angle is θ 2, the paper bundle T drops by its own weight and is loaded on the first paper ejection tray 16 with the rear end matched, and the stapling process of the sheets of paper P is completed.

Next, a case that the stapling process which is a post-process is to be performed and preceding sheets of paper P in execution of the stapling process remain on the processing tray 12 will be described. At this time, the standby tray 10 slides and moves the tray members 10 a and 10 b from the position indicated by the dashed line in FIG. 11 respectively in the opposite direction of the direction of the arrow m or in the opposite direction of the direction of the arrow n, and is moved to the position indicated by the solid line shown in FIG. 11, and can support the sheet of paper P. The standby tray roller 28 is shifted above the standby tray not to disturb the sheets of paper P. The sheets of paper P ejected from the image forming apparatus 5 and fed by the paper feed rollers 24 are loaded once on the standby tray 10 to wait for the processing tray 12 to be free.

The sheets of paper P loaded on the standby tray 10 are moved down onto the standby tray 10, are sent toward the standby stoppers 10 c and 10 d by the standby tray roller 28 rotating in the opposite direction of the direction of the arrow f, and are vertically matched with the rear end of the sheets of paper P in contact with the standby stoppers 10 c and 10 d. Furthermore, the first paper ejection tray 16 is arranged at a tilt angle of θ 1 and the front end of the sheets of paper is positioned higher than the rear end thereof, so that the sheets of paper P are vertically matched by the own weight with the rear end thereof in contact with the standby stoppers 10 c and 10 d.

The standby tray 10 is arranged at a tilt angle of θ 1, so that for example, even if the sheet of paper P is fed from the paper feed rollers 24 in a state that it is curled convexly and is fed to the standby tray 10, the preceding sheet of paper P loaded on the standby tray 10 is not pressed out by making contact with the front end of the succeeding sheet of paper P. Namely, the fed sheet of paper P is sequentially loaded on the standby tray 10 unless the order is disturbed. Further, even if the preceding sheet of paper P is pressed by the succeeding sheet of paper P and is slightly displaced, since the tilt angle is θ 1, the sheet of paper P drops by its own weight down to the position where the rear end thereof makes contact with the standby stoppers 10 c and 10 d and is loaded on the standby tray 10 with the rear end matched.

During this period, when the preceding sheet of paper P on the processing tray 12 is ejected on the side of the paper ejection tray 16 and the processing tray 12 becomes free, the standby tray 10 slides and moves the tray members 10 a and 10 b respectively up to the positions indicated by the dotted lines in FIG. 11 in the directions of the arrows m and n from the position indicated by the solid line in FIG. 11 via the position indicated by the alternate long and short dash line in FIG. 11. By doing this, for example, two sheets of paper P standing by on the standby tray 10, when the tray members 10 a and 10 b reach the position indicated by the alternate long and short dash line in FIG. 11, are dropped and fed onto the processing tray 12 from between the tray members 10 a and 10 b. At this time, the horizontal matching plates 47 a and 47 b are arranged so as to make the interval between them almost equal to the width of the sheets of paper P. Therefore, the sheets of paper P dropped from the standby tray 10 are controlled on both sides by the horizontal matching plates 47 a and 47 b and are matched horizontally.

The lower side sheet of paper P of the two sheets of paper P dropped onto the processing tray 12 is sent in the direction of the arrow q by the lower vertical matching roller 38 b rotating in the opposite direction of the direction of the arrow s, and the rear end of the sheet of paper P makes contact with the stopper 45, and the vertical matching of the sheet of paper P is completed. The upper side sheet of paper P of the two sheets of paper P dropped onto the processing tray 12 is sent in the direction of the arrow q by the upper vertical matching roller 38 a rotating in the opposite direction of the direction of the arrow r, and the rear end of the sheet of paper P makes contact with the stopper 45, and the vertical matching of the sheet of paper P is completed, and thereafter, the upper vertical matching roller 38 a is shifted upward.

The third and subsequent sheets of paper P ejected from the image forming apparatus 5 are directly dropped and fed onto the processing tray 12 from between the tray members 10 a and 10 b without standing by on the standby tray 10. Hereafter, the third and subsequent sheets of paper P are sequentially matched on the sheets of paper P loaded earlier on the processing tray 12 by the paddle 44.

When the sheets of paper P loaded on the processing tray 12 reach a predetermined number, the sheets are stapled by the stapler 14 to form a paper bundle T. Hereafter, the paper bundle T is conveyed toward the first paper ejection tray 16 by the upper and lower vertical matching rollers 38 a and 38 b, and furthermore the rear end thereof is hooked by the feed pawl 50 a of the conveyor belt 50, and the paper bundle is sent to the first paper ejection tray 16, and the stapling process of the sheets of paper P is completed.

In this embodiment having such a constitution, a dedicated path for non-post-process sheets of paper is installed and a sheet post-process apparatus free of reduction in the productivity of the image forming apparatus can be obtained. Furthermore, the time up to paper ejection can be shortened. The paper ejection tray receives either of the sheets of paper P which are post-processed and the sheets of paper P which are not post-processed, so that compared with a case that a non-post-process dedicated paper ejection tray is installed, a great decrease in cost is realized.

Further, the standby tray 10 is given a tilt angle of θ 1, thus the sheets of paper P can be matched by the own weight on the standby tray 10. There is no fear that the sheet of paper P loaded earlier is pressed out by the succeeding sheet of paper P, and the consistency of the sheets of paper P on the standby tray 10 can be improved, and the sheets of paper P can be prevented from jamming, and the loading order of the sheets of paper P on the standby tray 10 can be prevented from disturbance. Similarly, the first or second paper ejection tray 16 or 18 is given a tilt angle of θ 2, thus there is no fear that the sheets of paper P or the paper bundle T earlier loaded on the first or second paper ejection tray 16 or 18 is pressed out by the succeeding sheets of paper P or paper bundle T, and the consistency of the sheets of paper P on the first or second paper ejection tray 16 or 18 can be improved, and the sheets of paper P can be prevented from jamming, and furthermore the loading order of sheets of paper P or the paper bundle T on the first or second paper ejection tray 16 or 18 can be prevented from disturbance.

Further, in the present invention, as a post-process to be performed for sheets of paper loaded on the processing tray, the stapling process is described. However, the post-process is not limited to a case of stapling sheets of paper and for example, a post-process such as a hole-punching process in sheets of paper is not questionable. In this case, with respect to sheets of paper loaded on the processing tray, loading of one sheet instead of a plurality of sheets of paper provides no trouble. Needless to say, for a post-process apparatus having such a post-processing mechanism, the present invention produces an effect.

Although exemplary embodiments of the present invention have been shown and described, it will be apparent to those having ordinary skill in the art that a number of changes, modifications, or alterations to the invention as described herein may be made, none of which depart from the spirit of the present invention. All such changes, modifications, and alterations should therefore be seen as within the scope of the present invention. 

1. Sheet post-process apparatus comprising: a gate for branching sheets ejected from an image forming apparatus to a conveying path of sheets requiring a post process and a conveying path of sheets requiring no post process, an exclusive paper path of said sheets requiring no post process, a standby tray for making predetermined sheets among said sheets requiring said post process, a processing tray arranged under said standby tray for loading said sheets dropped and fed from said standby tray and/or said sheets ejected from said image forming apparatus not via said standby tray, a processing mechanism for post-processing said sheets loaded on said processing tray, and a paper ejection tray for loading said sheets ejected from said processing tray after ending of said post process and said sheets requiring no post process.
 2. The sheet post-process apparatus of claim 1, wherein: said gate has a wedge-shaped section.
 3. The sheet post-process apparatus of claim 1, wherein: said gate is rotatably born by an inner side wall of said sheet post-process apparatus.
 4. The sheet post-process apparatus of claim 1, further comprising: a pair of entrance rollers receiving said sheets ejected from said image forming apparatus which are arranged almost at upper and lower positions, wherein said gate takes a first position almost pointing an upper entrance roller and takes a second position almost pointing a lower entrance roller.
 5. The sheet post-process apparatus of claim 4, wherein: said first position is a position for selecting said path requiring said post process and said second position is a position for selecting said path requiring no post process.
 6. The sheet post-process apparatus of claim 4, wherein: when said gate is at said first position, said sheets are sent to said standby tray.
 7. The sheet post-process apparatus of claim 2, wherein: a plurality of paper feed rollers are installed before and after said paper path. 